Missing Data in the Context of Student Growth

One property of student growth data that is often overlooked despite widespread prevalence is incomplete or missing observations. As students migrate in and out of school districts, opt out of standardized testing, or are absent on test days, there are many reasons student records are fractured. Missing data in growth models can bias model estimates and growth inferences. This study presents empirical explorations of how well missing data methodologies recover attributes of would-be complete student data used for teacher evaluation. Missing data methods are compared in the context of a Student Growth Percentiles (SGP) model used by several school systems for accountability purposes. Using a real longitudinal dataset, we evaluate the sensitivity of growth estimates to missing data and compare the following missing data methods: listwise deletion, likelihood-based imputation using an expectation-maximization algorithm, multiple imputation using a Markov Chain Monte Carlo method, multiple imputation using a predictive mean matching method, and inverse probability weighting. Methodological and practical consequences of missing data are discussed

People's perceptions and classifications of sounds heard in urban parks : semantics, affect and restoration

Sounds have been broadly categorized by researchers into ‘human’, ‘nature’ and ‘mechanical’. It is less clear if the general public define and classify sounds in the same way and which factors influence their classification process. Establishing people’s classification and impression of urban park sounds helps identify their perception and experience of urban parks. This in turn aides the process of defining parks with reference to soundscapes, to produce an appreciated and potentially restorative place. This study involved urban park sounds, identified by park users, being presented in card sorts and survey items. Participants sorted the sounds into similar groups, in reference to a visited park. The terminology, factors involved and classification of the sounds was assessed using multidimensional scaling. Triangulation of the results suggests affect is a key factor in people’s classification process. Participants’ grouped sounds were labelled by affective terms more often than their perceived physical properties. Affective evaluations of each sound produced a similar classification structure as the card sort results. People’s classification structure also varied depending on how restorative they found their urban park. Furthermore schematic recollections played a part with many sounds being ‘expected’. Overall similarities and differences with ‘human’, ‘nature’ and ‘mechanical’ classifications were observed

Scaling up from greenhouse resistance to fitness in the field for a host of an emerging forest disease.

Forest systems are increasingly threatened by emergent, exotic diseases, yet management strategies for forest trees may be hindered by long generation times and scant background knowledge. We tested whether nursery disease resistance and growth traits have predictive value for the conservation of Notholithocarpus densiflorus, the host most susceptible to sudden oak death. We established three experimental populations to assess nursery growth and resistance to Phytophthora ramorum, and correlations between nursery-derived breeding values with seedling survival in a field disease trial. Estimates of nursery traits' heritability were low to moderate, with lowest estimates for resistance traits. Within the field trial, survival likelihood was increased in larger seedlings and decreased with the development of disease symptoms. The seed-parent family wide likelihood of survival was likewise correlated with family predictors for size and resistance to disease in 2nd year laboratory assays, though not resistance in 1st year leaf assays. We identified traits and seedling families with increased survivorship in planted tanoaks, and a framework to further identify seed parents favored for restoration. The additive genetic variation and seedling disease dynamics we describe hold promise to refine current disease models and expand the understanding of evolutionary dynamics of emergent infectious diseases in highly susceptible hosts

Goma: Centers for Internally Displaced Persons

The conflict in the Democratic Republic of Congo has claimed an estimated 5 million lives—it is the deadliest conflict since World War II. Despite a 2003 peace accord, fighting continues and according to the Internal Displacement Monitoring Centre over hundreds of thousands of people are now displaced, the majority of whom are within the eastern providence of North Kivu. In response to this crisis, UNICEF and partnering agencies have set up centers for the displaced population—providing them with, among other things, shelter, food, water, and schooling

Physical Activity Guidelines for People with Alzheimer’s Disease of Various Ambulatory and Cognitive Status

With the rapidly growing elderly population in the United States, the number of people diagnosed with dementia and Alzheimer’s Disease (AD) is increasing dramatically. For these patients, it is crucial to slow the rate of progression. Research has proven that exercise improves cognition, and recent findings suggest a similar association among those with AD. However, this is complicated by the large majority of AD patients becoming non-ambulatory as the disease progresses. Thus, there is a large gap in the literature to meet the needs of non-ambulatory AD patients working to slow their disease’s progression. The first purpose of this article is to summarize the existing research that demonstrates the positive effects that exercise has on the elderly and patients with AD. The second purpose is to provide activities that can enhance the cognitive and physical function of AD patients with various ambulatory and cognitive status. Recommendations for further research into various programs’ physiologic effects on AD patients are offered, as well as some tools that may help with data collection